Prospective medical data will be analyzed by multivariate statistical techniques to show the degree of relationship between physical work capacity (PWC 160) and coronary heart disease morbidity in context with other risk factors (blood pressure, blood cholesterol, triglycerides, glucose, uric acid, hemoglobin, overweight, skinfolds, electrocardiogram, smoking, family history, age, etc.). The population consists of a group of nine thousand safety and executive employees, over half of whom already have received complete cardiovascular examinations (including periodic standardized exercise electrocardiographic testing with measurement of oxygen consumption and physical work capacity.